Vitamin E supplementation in people with cystic fibrosis.

BACKGROUND: People with cystic fibrosis are at an increased risk of fat-soluble vitamin deficiency, including vitamin E. Vitamin E deficiency can cause a host of conditions such as haemolytic anaemia, cerebellar ataxia and cognitive difficulties. Vitamin E supplementation is widely recommended for people with cystic fibrosis and aims to ameliorate this deficiency. This is an updated version of the review. OBJECTIVES: To determine the effects of any level of vitamin E supplementation on the frequency of vitamin E deficiency disorders in people with cystic fibrosis. SEARCH METHODS: We searched the Cochrane Group's Cystic Fibrosis Trials Register and also searched international online trial registries for any ongoing clinical trials that were not identified during our register search. Date of last search of the Register: 11 August 2020. Date of last search of international online trial registries: 20 July 2020. SELECTION CRITERIA: Randomised controlled trials and quasi-randomised controlled trials comparing any preparation of vitamin E supplementation to placebo or no supplement, regardless of dosage or duration. DATA COLLECTION AND ANALYSIS: Two authors extracted outcome data from each study (published information) and assessed the risk of bias of each included study. They assessed the quality of the evidence using GRADE. MAIN RESULTS: Four studies with a total of 141 participants were included in the review, two of these were in children (aged six months to 14.5 years), and two did not specify participants' age. All studies used different formulations and doses of vitamin E for various durations of treatment (10 days to six months). Two studies compared the supplementation of fat-soluble as well as water-soluble formulations to no supplementation in different arms of the same study. A third study compared a water-soluble formulation to a placebo; and in the fourth study a fat-soluble formulation of vitamin E was assessed against placebo. There was limited detail about randomisation and blinding in the included studies which compromises the quality of the evidence base for the review. The heterogeneous mix of the formulations with differing biovailabilities among these studies also limits the generalisability of the data to the wider cystic fibrosis population. None of the studies in either comparison report the review's primary outcomes of vitamin E total lipid ratio or the incidence of vitamin E-specific deficiency disorders, or the secondary outcomes lung function or quality of life. Water-soluble vitamin E Water-soluble vitamin E may improve serum vitamin E levels compared with control at six months, one study (45 participants), mean difference (MD) 19.74 umol/L (95% confidence interval (CI) 13.48 to 26.00) (low-quality evidence). Similar results were also seen at one month, two studies (32 participants), MD 17.66 umol/L (95% CI 10.59 to 24.74) and at three months, one study (45 participants), MD 11.61 umol/L (95% CI 4.77 to 18.45). Only one study (45 participants) reported weight (secondary outcome of growth and nutritional status) at one and six months, but showed no difference between treatment and control at either time point. Fat-soluble vitamin E Two studies (36 participants) reported higher levels of serum vitamin E at one month with fat-soluble vitamin E compared with control, MD 13.59 umol/L (95% CI 9.52 to 17.66); however, at three months one study (36 participants) showed no difference between treatment and control. No studies in this comparison reported on growth or nutritional status. AUTHORS' CONCLUSIONS: Vitamin E supplementation may lead to an improvement in vitamin E levels in people with cystic fibrosis, although evidence we assessed was low quality. No data on other outcomes of interest were available to allow conclusions about any other benefits of this therapy. In future, larger studies are needed, especially in people already being treated with enteric-coated pancreatic enzymes and supplemented with vitamin E, to look at more specific outcome measures such as vitamin E status, lung function and nutritional status. Future studies could also look at the optimal dose of vitamin E required to achieve maximal clinical effectiveness.

Tocopherols, tocotrienols and tocomonoenols: Many similar molecules but only one vitamin E.

The aim of this article is to correct a very general error in scientific articles, in textbooks and in the Internet that has become an accepted fact. In this literature, the term "vitamin E″ is used for several similar molecules (both tocopherols and tocotrienols) that have never been shown to have vitamin property, i.e. a protective effect against the human deficiency disease. In fact, the name "vitamin E″ should only be used to define molecules that prevent the human deficiency disease "Ataxia with Vitamin E Deficiency" (AVED). Only one such molecule is known, α-tocopherol. This error may confuse consumers as well as medical doctors, who prescribe vitamin E without realizing that the current use of the name includes molecules of unknown, if not unwanted functions.

Effect of RRR-α-tocopherol supplementation on serum of breastfeeding women up to 60 days after delivery: a randomised controlled trial.

BACKGROUND: Maternal supplementation is a viable strategy to combat vitamin E deficiency in newborns, although a protocol for maternal vitamin E supplementation has not been defined. The present study assessed the effect of maternal supplementation in a single dose on the serum of postpartum women up to 60 days after delivery. METHODOLOGY: Fifty healthy breastfeeding women were recruited at two maternity hospitals both located in Natal, RN, Brazil. The participants were randomly allocated to a control group and a treatment group in a 1 : 1 ratio. Serum was collected 1, 20, 30 and 60 days after delivery. Immediately after the first collection, the treatment group received a single dose of 400 IU of RRR-α-tocopherol. α-Tocopherol was quantified by high-performance liquid chromatography. The usual dietary vitamin E intake was determined using four 24-h recalls, and intake adequacy was assessed based on the estimated average requirements for lactating women (16 mg day-1 ). RESULTS: The mean dietary vitamin E intakes of the both groups were similar (P > 0.05) and inadequate. The serum levels of α-tocopherol assessed at 1, 20, 30 and 60 days indicated adequate vitamin E status in both the control group (1194.6, 907.7, 910 and 748.6 µg dL-1 , respectively) and treatment group (1183.7, 956.0, 935.9 and 766.4 µg dL-1 , respectively). The comparison at each day showed no difference between treatments (P > 0.05). CONCLUSIONS: A single vitamin E supplement did not change the mean serum level of α-tocopherol in breastfeeding women; thus, it does not improve their vitamin E status in the first 60 days after delivery.

Vitamin E supplementation in people with cystic fibrosis.

BACKGROUND: People with cystic fibrosis are at an increased risk of fat-soluble vitamin deficiency including vitamin E. Vitamin E deficiency can cause a host of conditions such as haemolytic anaemia, cerebellar ataxia and cognitive difficulties. Vitamin E supplementation is widely recommended in cystic fibrosis and aims to ameliorate this deficiency. This is an updated version of the review. OBJECTIVES: To determine the effects of any level of vitamin E supplementation on the frequency of vitamin E deficiency disorders in people with cystic fibrosis. SEARCH METHODS: We searched the Cochrane Group's Cystic Fibrosis Trials Register and also searched international trial registers for any ongoing clinical trials that were not identified during our register search.Date of last search of the Register: 10 October 2016. Date of last search of international trial registers: 15 February 2017. SELECTION CRITERIA: Randomised controlled trials and quasi-randomised controlled trials comparing any preparation of vitamin E supplementation to placebo or no supplement, regardless of dosage or duration. DATA COLLECTION AND ANALYSIS: Two authors extracted outcome data from each study (published information) and assessed the risk of bias of each included study. MAIN RESULTS: Four studies with a total of 141 participants were included in the review, two of these were in children (aged six months to 14.5 years), and the other two did not specify participants' age. All studies used different formulations and doses of vitamin E for various durations of treatment (10 days to six months). Two studies compared the supplementation of fat-soluble as well as water-soluble formulations to no supplementation in different arms of the same study. A third study compared a water-soluble formulation to a placebo; and in the fourth study a fat-soluble formulation of vitamin E was assessed against placebo.At one month, three months and six months, water-soluble vitamin E significantly improved serum vitamin E levels compared with control: at one month, two studies, mean difference 17.66 (95% confidence interval 10.59 to 24.74); at three months, one study, mean difference 11.61 (95% confidence interval 4.77 to 18.45); and at six months, one study, mean difference 19.74 (95% confidence interval 13.48 to 26.00). At one month fat-soluble vitamin E significantly improved serum vitamin E levels compared with control: one month, two studies, mean difference 13.59 (95% CI 9.52 to 17.66). The findings at three months were imprecise; one study; mean difference 6.40 (95% confidence interval -1.45 to 14.25).None of the studies report the review's primary outcomes of vitamin E total lipid ratio or the incidence of vitamin E-specific deficiency disorders, or the secondary outcomes lung function or quality of life. Only one study, comparing water-soluble vitamin E with placebo, reported the secondary outcome of growth and nutritional status (weight), but the results are uncertain due to imprecision around the effect estimate.There was limited detail about randomisation and blinding in the included studies which compromises the quality of the evidence base for the review. The heterogeneous mix of the formulations with differing biovailabilities among these studies also limits the generalisability of the data to the wider cystic fibrosis population. AUTHORS' CONCLUSIONS: Vitamin E supplementation led to an improvement in vitamin E levels in people with cystic fibrosis, although the studies may have been at risk of bias. No data on other outcomes of interest were available to allow conclusions about any other benefits of this therapy.In future, larger studies are needed, especially in people already being treated with enteric-coated pancreatic enzymes and supplemented with vitamin E, to look at more specific outcome measures such as vitamin E status, lung function and nutritional status. Future studies could also look at the optimal dose of vitamin E required to achieve maximal clinical effectiveness.

Vitamin E intake, α-tocopherol levels and pulmonary function in children and adolescents with cystic fibrosis.

Pancreatic insufficiency cystic fibrosis (CF) patients receive vitamin E supplementation according to CF-specific recommendations in order to prevent deficiencies. It has been suggested that higher serum α-tocopherol levels could have protective effects on pulmonary function (PF) in patients with CF. Whether current recommendations are indeed optimal for preventing deficiency and whether vitamin E has therapeutic benefits are subjects of debate. Therefore, we studied vitamin E intake as well as the long-term effects of vitamin E intake, the coefficient of fat absorption (CFA) and IgG on α-tocopherol levels. We also examined the long-term effects of serum α-tocopherol and serum IgG on forced expiratory volume in 1 s expressed as percentage of predicted (FEV1% pred.) in paediatric CF patients during a 7-year follow-up period. We found that CF patients failed to meet the CF-specific vitamin E recommendations, but serum α-tocopherol below the 2·5th percentile was found in only twenty-three of the 1022 measurements (2 %). Furthermore, no clear effect of vitamin E intake or the CFA on serum α-tocopherol was found (both P≥ 0·103). FEV1% pred. was longitudinally inversely associated with age (P< 0·001) and serum IgG (P= 0·003), but it was not related to serum α-tocopherol levels. We concluded that in the present large sample of children and adolescents with CF, vitamin E intake was lower than recommended, but serum α-tocopherol deficiency was rare. We found no evidence that higher serum α-tocopherol levels had protective effects on PF. Adjustment of the recommendations to the real-life intake of these patients may be considered.

Maternal supplementation with natural or synthetic vitamin E and its levels in human colostrum.

OBJECTIVES: Newborns are considered a high-risk group for vitamin E deficiency. Breast milk is a source of alpha-tocopherol (α-TOH), a form of vitamin E that prevents deficiency. The present study aimed to assess whether supplementation with a natural or synthetic form of α-TOH, in addition to maternal sources of vitamin E, would increase the concentration of α-TOH in colostrum. METHODS: A total of 109 healthy lactating women were recruited from a Brazilian public maternity clinic and randomized into 3 groups: control without supplementation (n = 36), natural α-TOH supplementation (n = 40), and synthetic α-TOH supplementation (n = 33). Blood and colostrum samples were collected before and after supplementation to check the nutritional status of these women by high-performance liquid chromatography. The Kruskal-Wallis test was applied for independent samples, and Tukey test was used for 2-way analysis of the averages of the groups. The baseline nutritional status of vitamin E of all of the lactating women enrolled in the trial was considered adequate. RESULTS: Women who received supplementation had higher concentrations of α-TOH in colostrum than the control group, with 57% and 39% increases in women supplemented with the natural and synthetic forms of α-TOH, respectively. CONCLUSIONS: Supplementation with both forms of α-TOH increased vitamin E concentrations in colostrum; however, the natural form was more efficient in increasing the levels.

Vitamin E supplementation in people with cystic fibrosis.

BACKGROUND: People with cystic fibrosis are at an increased risk of fat-soluble vitamin deficiency including vitamin E. Vitamin E deficiency can cause a host of conditions such as haemolytic anaemia, cerebellar ataxia and cognitive difficulties. Vitamin E supplementation is widely recommended in cystic fibrosis and aims to ameliorate this deficiency. OBJECTIVES: To determine the effects of any level of vitamin E supplementation on the frequency of vitamin E deficiency disorders in people with cystic fibrosis. SEARCH METHODS: We searched the Cochrane Group's Cystic Fibrosis Trials Register and also searched international trial registers for any ongoing clinical trials that were not identified during our register search.Date of last search of the Register: 10 February 2014. Date of last search of international trial registers: 30 August 2014. SELECTION CRITERIA: Randomised controlled trials and quasi-randomised controlled trials comparing any preparation of vitamin E supplementation to placebo or no supplement, regardless of dosage or duration. DATA COLLECTION AND ANALYSIS: Two authors extracted outcome data from each study (published information) and assessed the risk of bias of each included study. MAIN RESULTS: Four studies with a total of 141 participants were included in the review, two of these were in children (aged six months to 14.5 years), and the other two did not specify participants' age. All studies used different formulations and doses of vitamin E for various durations of treatment (10 days to six months). Two studies compared the supplementation of fat-soluble as well as water-soluble formulations to no supplementation in different arms of the same study. A third study compared a water-soluble formulation to a placebo; and in the fourth study a fat-soluble formulation of vitamin E was assessed against placebo.At one month, three months and six months, water-soluble vitamin E significantly improved serum vitamin E levels compared with control: at one month, two studies, mean difference 17.66 (95% confidence interval 10.59 to 24.74); at three months, one study, mean difference 11.61 (95% confidence interval 4.77 to 18.45); and at six months, one study, mean difference 19.74 (95% confidence interval 13.48 to 26.00). At one month fat-soluble vitamin E significantly improved serum vitamin E levels compared with control: one month, two studies, mean difference 13.59 (95% CI 9.52 to 17.66). The findings at three months were imprecise; one study; mean difference 6.40 (95% CI -1.45 to 14.25).None of the studies report the review's primary outcomes of vitamin E total lipid ratio or the incidence of vitamin E-specific deficiency disorders, or the secondary outcomes lung function or quality of life. Only one study, comparing water-soluble vitamin E with placebo, reported the secondary outcome of growth and nutritional status (weight), but the results are uncertain due to imprecision around the effect estimate.There was limited detail about randomisation and blinding in the included studies which compromises the quality of the evidence base for the review. The heterogeneous mix of the formulations with differing biovailabilities among these studies also limits the generalisability of the data to the wider cystic fibrosis population. AUTHORS' CONCLUSIONS: Vitamin E supplementation led to an improvement in vitamin E levels in people with cystic fibrosis, although the studies may have been at risk of bias. No data on other outcomes of interest were available to allow conclusions about any other benefits of this therapy.In future, larger studies are needed, especially in people already being treated with enteric-coated pancreatic enzymes and supplemented with vitamin E, to look at more specific outcome measures such as vitamin E status, lung function and nutritional status. Future studies could also look at the optimal dose of vitamin E required to achieve maximal clinical effectiveness.

Status of vitamins A and E in schoolchildren in the centre west of Tunisia: a population-based study.

OBJECTIVE: The present study was undertaken to assess the status of vitamins A and E (VA and VE, respectively) and their main determinants in Tunisian children. DESIGN: Cross-sectional population-based study. SETTING: Kasserine Governorate in the centre west of Tunisia. SUBJECTS: A total of 7407 children attending the first grade of elementary school were included. VA and VE were assessed by HPLC. RESULTS: The prevalence of moderate VA deficiency (VAD; <0·70 µmol/l) was 2·3 % and VE deficiency (VED; <6·97 µmol/l) was 5·4 %. Low status in VA (0·70-1·05 µmol/l) and VE (6·97-11·61 µmol/l) was observed in 17 % and 20·2 % of children, respectively. No child exhibited severe VA or VE deficiency (<0·35 and <2·32 µmol/l, respectively). The main predictors of VAD were advanced age (OR = 1·65; 95 % CI 1·13, 2·41; P = 0·05) and sickness within the past 2 weeks (OR = 1·51; 95 % CI 1·09, 2·09; P = 0·01). Predictors of VED were living in the peri-urban region (OR = 1·60; 95 % CI 1·28, 2·01; P < 0·001) and sickness within the past 2 weeks (OR = 0·75; 95 % CI 0·60, 0·94; P = 0·01). CONCLUSIONS: Moderate VAD and VED were uncommon in Tunisian children. However, low status in VA and/or VE remains frequent. A reinforcement of the national strategies for children's nutrition and health is needed, particularly in disadvantaged regions. Supplementation of VA and VE is not necessary in Tunisia, but food fortification may be beneficial.

Alpha-tocopherol concentration in the colostrum of nursing women supplemented with retinyl palmitate and alpha-tocopherol.

BACKGROUND: Vitamins A and E are recognisably important in the initial stages of life, and the newborn depends on nutritional adequacy of breast milk to meet their needs. These vitamins share routes of transport to the tissues and antagonistic effects have been observed in animals after supplementation with vitamin A. The present study aimed to determine the effect of maternal supplementation with a megadose of retinyl palmitate in the immediate post-partum on α-tocopherol concentration in the colostrum. METHODS: Healthy parturient women at a Brazilian public maternity were recruited for the study and divided into two groups: control (n = 37) and supplemented (n = 36). Blood and colostrum samples were collected up to 16 h post-partum. The supplemented group was administered with a retinyl palmitate capsule and, 24 h after the first collection, the second colostrum sample was obtained in the two groups for analysis of α-tocopherol. The cut-off points for deficiency are <1.05 µmol L(-1) for retinol and <11.6 µmol L(-1) for α-tocopherol. RESULTS: The mean (SD) serum concentration of 1.77 (0.50) µmol L(-1) for retinol and 30.81 (6.46) µmol L(-1) for α-tocopherol indicates an adequate biochemical status. The supplemented group showed an increase of α-tocopherol in the colostrum 24 h after supplementation (P = 0.04), and this finding was not observed in the control group. CONCLUSIONS: Supplementation with a 200,000 IU megadose of vitamin A did not negatively affect α-tocopherol levels in colostrum.

Dietary counseling in the management of moderate malnourishment in children.

BACKGROUND: Dietary counseling is an integral part of treating malnutrition. A first step toward improving the management of moderate malnutrition is to evaluate dietary messages in current programs and assess their adequacy and effectiveness. OBJECTIVES: To ascertain current recommendations regarding family foods for the treatment of moderate malnutrition and assess whether these are likely to meet nutritional requirements for rehabilitation; to review the effectiveness of dietary counseling in the management of moderate malnutrition. METHODS: Information was requested from 10 United Nations agencies or donors, 20 international nongovernmental organizations, 3 pediatric associations, and 6 national programs about the dietary advice they give to caregivers of moderately malnourished children. Adequacy was assessed by comparing dietary recommendations with nutritional requirements. Linear programming was used to identify problem nutrients. A literature search was conducted of studies using family foods for rehabilitating malnourished children. RESULTS: There was a greater emphasis on providing food supplements for rehabilitation than on utilizing family foods. Dietary recommendations were mostly vague and unlikely to be effective. Those developed by the World Health Organization and the Food and Agriculture Organization for well-nourished children may meet nutritional requirements in moderate malnutrition if the recommendations are made more prescriptive. Zinc and vitamin E emerged as possible problem nutrients. Intervention studies in wasted children suggest that counseling caregivers about family foods can achieve good rates of weight gain. CONCLUSIONS: Dietary counseling can be effective in managing malnutrition, but it is often weak or absent and should be strengthened. More attention will need to be given to formulating the messages and improving counseling skills.

Vitamin E.

Vitamin E refers to a family of tocopherol and tocotrienol isomers discovered in 1922 as anti-infertility factor. Vitamin E deficiency causes infertility and delayed-onset ataxia in experimental animals, and it leads to neuronal dysfunctions in humans. However, based largely on its radical-scavenging antioxidant activity in vitro, vitamin E supplements are commonly thought to provide health benefits against diseases associated with oxidative damage, most notably cardiovascular diseases. Contrary to this belief, the outcome of recent large, prospective, randomized and placebo-controlled clinical studies does not encourage the use of vitamin E supplements. These overall disappointing results can be explained and substantiated by scientific data critically testing the strengths of evidence for many of the underlying assumptions and examining the possibility that in vivo vitamin E may have function(s) other than, or in addition to, acting as an antioxidant.

Vitamin E regulatory mechanisms.

Dietary and supplemental vitamin E is absorbed and delivered to the liver, but of the various antioxidants with vitamin E activity, only alpha-tocopherol is preferentially recognized by the alpha-tocopherol transfer protein (alpha-TTP) and is transferred to plasma, while the other vitamin E forms (e.g., gamma-tocopherol or tocotrienols) are removed from the circulation. Hepatic alpha-TTP is required to maintain plasma and tissue alpha-tocopherol concentrations. The liver is the master regulator of the body's vitamin E levels in that it not only controls alpha-tocopherol concentrations, but also appears to be the major site of vitamin E metabolism and excretion. Vitamin Es are metabolized similarly to xenobiotics; they are initially omega-oxidized by cytochrome P450s, undergo several rounds of beta-oxidation, and then are conjugated and excreted. As a result of these various mechanisms, liver alpha-tocopherol and other vitamin E concentrations are closely regulated; thus, any potential adverse vitamin E effects are limited.

Vitamin E status in children with cystic fibrosis and pancreatic insufficiency.

Vitamin E status was compared in 69 children (7.0-10.0 years) with cystic fibrosis and pancreatic with the National Health and Nutrition Examination Survey III sample (6.0-11.9 years). With median vitamin E intakes of 6 mg/day (dietary) and 224 mg/day (supplemental), children with cystic fibrosis had higher serum alpha-tocopherol:cholesterol ratios, higher alpha-tocopherol, and lower cholesterol levels than in the National Health and Nutrition Examination Survey.

Dietary supplementation with 3-deaza adenosine, N-acetyl cysteine, and S-adenosyl methionine provide neuroprotection against multiple consequences of vitamin deficiency and oxidative challenge: relevance to age-related neurodegeneration.

Folate deprivation induces neurotoxicity that is potentiated by additional nutritional and genetic deficiencies including vitamin E and apolipoprotein E deficiency. These deficiencies collectively induce oxidative damage, cognitive impairment, and compensatory alteration in glutathione generation. Treatment with agents that regulate distinct portions of the methionine cycle, including the S-adenosyl homocysteine hydrolase inhibitor, 3-deaza adenosine, the methyl donor S-adenosyl methionine, and the antioxidant N-acetyl cysteine, provide neuroprotection against various aspects of neurotoxicity in normal and apolipoprotein E-deficient mice and in cultured neuronal cells deprived of dietary folate and vitamin E and subjected to iron overload. Here it is demonstrated that simultaneous treatment with these agents provide superior neuroprotection by alleviating individual and overlapping neurotoxic consequences. These findings support combinatorial treatments with agents that compensate for differential insults in age-related neurodegenerative disorders.

Effects of vitamin E and carotenoid status on oxidative stress in health and disease. Evidence obtained from human intervention studies.

Vitamin E and carotenoids are known to act as antioxidants both in vitro and in vivo. In this review we present a series of studies in healthy subjects and in patients who exhibit either acute or chronic oxidative stress. In the EU-Commission funded VITAGE project we investigated the status and effects of vitamin E and carotenoids on oxidative stress in 300 healthy volunteers. Depletion studies limiting dietary vitamin E or carotenoid intake to approximately 25% of the dietary reference intakes and subsequent repletion by supplementation with either large doses of vitamin E or intermediate doses of carotenoids showed significant changes in ex vivo LDL oxidizability, total plasma peroxide concentrations and urinary 8-oxo-7,8-dihydro-2(')-deoxyguanosine excretion. Patients on chronic hemodialysis present with oxidative stress in the presence of normal vitamin E but impaired vitamin C status and, due to anemia, need to be treated with parenteral iron. We studied the effects of a single oral dose of vitamin E taken 6 h prior to intravenous infusion of 100 mg iron, which exceeded the iron-binding capacity of transferrin. Vitamin E significantly reduced and in combination with a single dose of vitamin C completely abrogated acute oxidative stress induced by the iron load. Patients with cystic fibrosis are exposed to chronic oxidative stress due to an overproduction of reactive oxygen species as a result of neutrophil-dominated lung inflammation and impaired antioxidant status. Biochemical vitamin E and carotenoid deficiencies could be fully corrected even in the presence of fat malabsorption using intermediate doses of either RRR alpha-tocopherol or all-rac alpha-tocopheryl acetate and water-miscible all-trans beta-carotene. Long-term supplementation reduced ex vivo LDL oxidizability, in vivo lipid peroxidation and lung inflammation.

gamma-tocopherol, the major form of vitamin E in the US diet, deserves more attention.

gamma-tocopherol is the major form of vitamin E in many plant seeds and in the US diet, but has drawn little attention compared with alpha-tocopherol, the predominant form of vitamin E in tissues and the primary form in supplements. However, recent studies indicate that gamma-tocopherol may be important to human health and that it possesses unique features that distinguish it from alpha-tocopherol. gamma-Tocopherol appears to be a more effective trap for lipophilic electrophiles than is alpha-tocopherol. gamma-Tocopherol is well absorbed and accumulates to a significant degree in some human tissues; it is metabolized, however, largely to 2,7,8-trimethyl-2-(beta-carboxyethyl)-6-hydroxychroman (gamma-CEHC), which is mainly excreted in the urine. gamma-CEHC, but not the corresponding metabolite derived from alpha-tocopherol, has natriuretic activity that may be of physiologic importance. Both gamma-tocopherol and gamma-CEHC, but not alpha-tocopherol, inhibit cyclooxygenase activity and, thus, possess antiinflammatory properties. Some human and animal studies indicate that plasma concentrations of gamma-tocopherol are inversely associated with the incidence of cardiovascular disease and prostate cancer. These distinguishing features of gamma-tocopherol and its metabolite suggest that gamma-tocopherol may contribute significantly to human health in ways not recognized previously. This possibility should be further evaluated, especially considering that high doses of alpha-tocopherol deplete plasma and tissue gamma-tocopherol, in contrast with supplementation with gamma-tocopherol, which increases both. We review current information on the bioavailability, metabolism, chemistry, and nonantioxidant activities of gamma-tocopherol and epidemiologic data concerning the relation between gamma-tocopherol and cardiovascular disease and cancer.

Dehydroepiandrosterone (DHEA) sulfate prevents reduction in tissue vitamin E and increased lipid peroxidation due to murine retrovirus infection of aged mice.

Dietary effects of dehydroepiandrosterone sulfate (DHEAS) supplementation on tissue antioxidants and lipids were investigated in retrovirus infected mice. DHEA is a powerful antioxidant and immunomodulator whose production declines with age. For this study, twenty-four female, 15-month-old C57BL/6 mice were left uninfected while twenty-four were infected with LP-BM5 murine leukemia virus, causing murine AIDS. The retroviral infection caused immune dysfunction and loss of hepatic and cardiac vitamins E and A, resulting in increased lipid peroxides. Treatment with DHEAS at 0.01 or 0.005% in drinking water for 10 weeks post-infection significantly (P < 0.05) lowered lipid peroxidation in both heart and liver tissues. Treatment with DHEAS also largely prevented loss of the antioxidants, such as vitamin E and A, and prevented loss of phospholipid in the hearts and livers of the old uninfected as well as infected mice. This study suggests that DHEAS supplementation reduces damage associated with elevated oxidation due to aging and retrovirus infection.